In related art, a process cartridge which is attached to an image forming apparatus employing an electrophotographic system has been known. The process cartridge is attached to the image forming apparatus in a state where an inside thereof is filled with toner.
As such a process cartridge, a process cartridge including a cartridge frame in which a toner developing frame and a cleaning frame are coupled is known. This process cartridge includes developing means, such as a photosensitive drum and a developing roller, in the cartridge frame. In the cartridge frame, the toner developing frame includes a toner containing section and a toner filling port. In the process cartridge, the toner containing section is filled with toner through the toner filling port. The process cartridge in this state is attached to the image forming apparatus. When an image forming operation is started, the toner in the toner containing section is supplied to the developing roller through a toner supply opening and the toner moves from the developing roller to the photosensitive drum.
In the above-described process cartridge, the toner containing section is filled with toner in a state where the toner supply opening is sealed with a toner sealing member. Accordingly, in an unused process cartridge, there is a possibility that only the toner containing section is filled with toner and toner is not uniformly provided to the vicinity of the developing roller.
When such an unused process cartridge is attached to an image forming apparatus, a certain time is required until the developing roller carries the toner after the image forming operation is started. As a result, image formation failure may occur just after the image forming operation is started.